Characterization of cross-linked gelatin nanofibers through electrospinning

Abstract

Gelatin nanofibers can be used in the development of a biomimicking artificial extra cellular matrix(ECM) for tissue engineering, wound healing dressings and drug release. However, gelatin nanofibers are water soluble and have weak mechanical strength. Two different cross-linking methods for preparing gelatin nanofibers were used to render gelatin nanofibres insoluble: 1) UV radiation for modified gelatin nanofibers by trans-cinnamic acid; and 2) electrospun gelatin nanofibers cross-linked with genipin. A photo cross-linking method was used to examine the effects of ultraviolet (UV) radiation on the modified gelatin nanofiber scaffolds. A modified gelatin solution containing gelatin, trans-cinnamic acid and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) at a molar ratio of 1:3:30 was prepared. The results showed that the degree of modification in gelatin molecules was 14.5 groups per mol. The modified gelatin was dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol at 20%(w/v) and nanofibrous meshes were obtained by electrospinning. After drying, the nanofibrous meshes were exposed to a commercial germicide UV (=254 nm) lamp for different times. The swelling ratio of each nanofibrous mesh was decreased from 195% to 105% with increasing UV exposure time from 1 h to 10 h. A cross-linking agent method was used to evaluate the effects of the cross-linked gelatin nanofiber scaffolds with genipin. The swelling ratios decreased from 725% to 445% with increasing genipin solution concentration from 0.5%(w/ v) to 2%(w/v). The results of the cell culture suggest that cross-linking gelatin nanofibers with 0.5%(w/v) genipin improves the level of cell proliferation with increasing cell culture time from 1 day to 5 days. Moreover, the cell viability of each nanofiber increased with increasing cell culture time. However, the cell viability decreased with increasing genipin solution concentration.

A UV-cured nanofibrous membrane of vinylbenzylated gelatin-poly(ɛ-caprolactone) dimethacrylate co-network by scalable free surface electrospinning

“…In light of its non-toxicity, biodegradability, biocompatibility, formability and low-cost commercial availability [20], gelatin has been excessively used as building block for the design of smart wound dressing and healing materials [21,22], pharmaceuticals [23], personal care [24] and food industry products [25], as well as drug delivery systems [26][27][28] and scaffolds for tissue engineering [29]. However, electrospun gelatin typically present uncontrollable water-induced swelling and dissolution, and display weak mechanical strength in the hydrated state, which substantially limit long-term fibre performance [30].…”

“…In light of the presence of amine and carboxylic groups along gelatin backbones, various chemical treatments have been proposed to introduce covalent crosslinks lost following collagen extraction and denaturation ex vivo, so that micro-/macroscopic structural features and mechanical properties of hydrated gelatin nanofibre membranes could be controlled [31]. Crosslinking strategies have been pursued by carbodiimide chemistry [29,[32][33][34], bifunctional compounds such as glutaraldehyde (GTA) [33,[35][36][37][38][39][40][41][42] and genipin [30,43,44], silanisation [41], dehydrothermal [46] and plasma treatments [47], as well as via ultraviolet (UV) light [30,[48][49][50]. Although chemical crosslinking is the most widely used method, crosslinking agents are often associated with risks of cytotoxicity and calcification in host polymer scaffolds [51][52][53], are unable to ensure fibrous retention and minimal membrane dissolution in aqueous media [30,48,54], may cause thermal degradation of gelatin [55,56], or may lead to side reactions, resulting in hardly-controllable process-structure-property relationships.…”

Enhancement of Fibroblasts Outgrowth onto Polycaprolactone Nanofibrous Grafted by Laminin Protein Using Carbon Dioxide Plasma Treatment

“…Laminin is a component of the basement membrane and contains the RGD sequence (contains the three-amino-acid sequence arginineglycine-aspartic acid binding sequence that reacts with integrin receptors on the growth cone and promotes cellular adhesion) that aids in cell adhesion and the five aminoacid sequence isoleucine-lysine-valine-alaninevaline sequence that controls neurite outgrowth [11]. Ko et al used laminin as the contact guidance biochemical cues for axonal outgrowth [12]. Laminin is one of the ECM component that is continuously synthesized after nerve injury and it plays a crucial role in cell migration, differentiation and axonal growth [13].…”

Electrospinning of gelatin for tissue engineering – molecular conformation as one of the overlooked problems

“…Although the mechanism of genipin crosslinking is still under discussion, it is known that genipin crosslinked gelatin is about 10,000 times less cytotoxic than GTA crosslinked gelatin. [50] Genipin was also used in [12,51]. The next alternative to the commonly used crosslinking agents is D,L-Glyceraldehyde, which is a natural product of metabolic processes.…”